


A Case in the Woods

by Aisu



Category: Sherlock (TV), Slender Man Mythos
Genre: Crossover, Gen, Horror, Psychological Horror
Language: English
Status: In-Progress
Published: 2012-01-29
Updated: 2012-02-12
Packaged: 2017-10-30 07:50:58
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 4
Words: 5,010
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/329487
Author URL: https://archiveofourown.org/users/Aisu/pseuds/Aisu
Summary: <blockquote class="userstuff">
              <p>Sherlock takes on a new case, but it might be one he's unable to solve - and it might take away his sanity, his hope, and the people he cares for most. Will he listen to his brother's warnings, or will this be the case that destroys Sherlock at last? A crossover with the Slender Man Mythos, with a strong focus on psychological horror.</p>
            </blockquote>





	1. Chapter 1

It was a strange case, more than worthy of Sherlock’s attentions. Bags found in Penn Wood - standard plastic garbage bags - that had been hung from trees and seemingly not discovered for weeks. A curious hiker had cut one down and opened it, finding inside a copious amount of blood and a young girl’s body, completely hollowed out from within.

Police had swarmed to the scene once the poor man had recovered the composure to make a phone call. All of the dozen bags had proven to be the same - blood and corpses, every one. Most of those killed seemed to be younger than 14 or so, with one outlying case who was maybe 20. All had been cleanly hollowed out. Some showed signs of undernourishment in the body they had left - thin, bony arms and hollow cheeks, patchy hair.

Lestrade had made the call an hour later, and Sherlock and John had arrived in fifteen minutes.

“This is the grove where they were found, correct?” Sherlock asked, looking around the clearing. John watched his face, not wanting to look at the trees that seemed to close in on him, the patches of blood where bags had been opened, the crumpled black bags themselves. The scene had been left as untouched as possible.

Lestrade nodded. “All in a circle. This is off all the major trails, and the bodies all seem to have been here for different amount of times… none of them touched by animals, though, which is a little odd.”

“Fascinating,” Sherlock murmured, starting to walk in a wide circle around the grove as John trailed close behind. He ducked out of the ring of trees once or twice, and John watched as he began to frown. “…There’s no way for them to have gotten here.”

John blinked. “Well, they have to have, I mean…”

Sherlock shook his head. “They weren’t killed here. The most recent was a day or two old, correct? There would be blood traces left from what he had done, and far more crushed leaves and the like, but there’s nothing. Similarly, the bodies were heavy and the bags were not perfectly sealed - or entirely sturdy. If the bags had been brought in from outside the clearing, there would be traces of wear on them from being dragged, and disturbances outside the clearing. Crushed leaves, blood drops, the works. But there’s nothing. Nothing at all. As if the bags just appeared hanging here.” He paused. “Does forensics have an idea for the weapon?”

“A knife,” Lestrade replied. “A damn sharp one, from the looks of it. The cuts were the cleanest we’ve seen in a long time.”

“Hmn.” Sherlock frowned a little, making his way to one of the trees and brushing his fingers across the bark. “And what do you make of this?”

Carved into the trunk - a little crudely, the lines a little shaky - was a symbol.

A large X overlapping a simple circle.

—-  
In the end, the day’s observations turned up little more. Some of the victims were identified, the police and Sherlock managing it together, and proved to have no connection with each other or with the woods. The man - the oldest of the victims - was left unidentified entirely.

The only oddity came when John made the difficult journey to one single mother’s house, at Sherlock’s request. He argued again and again that the woman needed time to mourn, to calm down, but Sherlock told him that she’d be likely to tell him more when her emotions were fresh, and at last John went.

In the end, she seemed quite cooperative and willing to help when John said what he was investigating. She was quiet, and she sniffled and dabbed at her eyes, but she told John everything she could.

“She’d been acting strangely for weeks,” she said softly. “We had to get her old nightlight out - she had outgrown it years ago, but now she just screamed and screamed when I turned out the lights. She had been so proud of being too big for it, too. She drew all the time during the day, she wouldn’t speak to me, she wouldn’t eat…” The woman swallowed. “I thought maybe she’d just run away. That we’d get a call from the police in a week when she turned up again, and she’d come home, and we’d be a family again. Proper. But…”

“I’m so sorry for your loss, ma’am,” John said as gently as he could, resting a hand on her shoulder. “I know it’s hard.”

The woman shook her head, blinking away tears. “I-it’s alright. I’ll… keep on somehow. Mother’s said I can live with her again for a while until I get settled.” She looked up at John. “…Would you like to see the drawings? They were so strange, and they worried me so much. I thought maybe they were of her father - I’d told her that he had been a businessman before he died, and I thought maybe she was drawing him, but… they were so strange.”

John nodded. “That might well be helpful. Thank you so much for your time.”

She gave him a small, fragile smile. “Anything to keep any more girls being hurt like my little Jenny.”

Jenny’s bedroom was a small, cozy room, decked out in pinks and princess memorabilia appropriate for a nine-year-old, but the chaos of papers across the floor was something else, something strange and out of place.

“I just couldn’t bear to clean it up,” the mother said softly.

John picked up one paper, studying it.

Depicted in crude, almost violent crayon-work was a tall, thin man in what was presumably a suit and tie. His limbs seemed long and disproportionate even for a child’s work, and, disturbingly, his face was just an oval, totally devoid of features.

And next to the man was an X crossing a circle, the mark drawn so violently into the paper that it had almost ripped.

“C-can I take this with me?” John asked, and the woman silently nodded.

—-

That night, John headed out to go shopping, wanting something simple and mundane to distract him from the oddities that were already popping up in the case. Sherlock was scrutinizing Jenny’s drawings, studying every aspect of them with a fascination and excitement that almost disturbed John a little. Still, it was what he expected from Sherlock nowadays.

As he headed along the street, though, his plans for a normal night were interrupted when every payphone and business phone on the block began ringing.

John groaned and closed his eyes. “Can’t you just send me a text for once, you melodramatic bastard?” he said to the skies.

But when the black car pulled up, John stepped in anyways, discovering for once that his seatmate wasn’t the enigmatic Anthea but instead Mycroft himself.

“Rare to see you out,” John commented, pulling his seatbelt down.

“This is a rather… urgent matter, John,” Mycroft replied, tenting his fingers. John sometimes wondered if either brother noticed that they shared the same sets of mannerisms. He wasn’t going to be the one to point it out. “Sherlock’s taken on a new case, correct?”

John nodded. “Bodies in the woods. It’s a weird one, to say the least. He—”

“—will drop it, right away,” Mycroft said, interrupting him.

John stared. “Sherlock Holmes? Drop a case? Are you kidding me?”

“I assure you, I am entirely serious, John. This is a state matter, and one he does not need to concern himself with.” Mycroft’s eyes narrowed.

“What, killing children and putting them in bags in the woods is essential to state security?” John felt his anger begin to rise in him, just a little.

“It’s not something we condone. But it is not something my brother can stop.” And for a moment - just a moment - something unfamiliar flashed across Mycroft’s impassive face. Concern. Compassion.

Fear.

“We know exactly what is happening, but because of that I cannot tell you. All I can tell you is that if you and Sherlock do not quit the investigation now, things will end up…” Mycroft hesitated. “…Just please. I can’t tell him to stop. He’d continue just to spite me. But I assure you, this is no threat, no attempt to keep you away from secrets because they are secret. This is to save both your lives.”

John shook his head. “I can’t stop Sherlock when he’s on a case,” he murmured. “Not when he’s deep into it. You know how his mind is. Once he has a trail…”

Mycroft smiled, but it was a thin, weak thing, barely a smile at all. “I understand. Thank you, John.” He hesitated a moment more. “…Whatever happens. Stay with him. He’ll need you more than ever.”

And with that, the car pulled over to the curb, and John climbed out, thoughtful and suddenly worried.

He had never seen Mycroft show terror before.

And he worried for what it meant.

—-

_That night John dreamed of sand, and blood, and screaming, and the firing of guns. That was all what he had come to expect from his nights - endless replays of the same movie, a movie that ended with aching pain in his shoulder and, on the worst nights, screams that woke Sherlock up._

_But tonight something else intruded, while John laid bleeding on the sand with a bullet deep in his shoulder - a figure that blocked out the scorching desert sun, that reached down with countless writhing limbs that felt slick and dry at once as they wrapped around John and lifted him up almost tenderly. They tasted at the blood at his shoulder. They tasted his skin, his eyes, his thoughts, his soul._

_And at last the figure lifted John to its face that was not a face at all and swallowed him whole._

He woke up coughing hard, his throat sore, his body chilled.

He could not explain why he was smiling.


	2. Chapter 2

**Summary for the Chapter:**

> A development is made in the case, bringing with it new leads - but also facts that confuse things all the more.

Breakfast was strange, even for 221B. John knew, of course, that Sherlock never ate on a case except for the barest amount, and so he was expecting the man to simply sit there poring over crayon drawings while John ate. What John couldn’t explain was why, after spending yesterday roaming around Penn Wood and then all of London, he had no appetite of his own.

Finally he gave up on picking at his food and looked up at Sherlock. “Work anything out yet?” he asked.

“Nothing yet,” Sherlock replied. “I made a few calls yesterday evening while you were out shopping, to the other parents we’ve identified. All the children were apparently doing about the same thing - drawing or talking about our faceless businessman, and writing that damn symbol anywhere they could.”

John frowned at that. “A kidnapper wearing a mask, maybe?”

“Unlikely. The behavior patterns are strange for a kidnapper. Would any kidnapper let their target see them so often during the initial examination? And the limbs…” Sherlock frowned, shaking his head. “It’s something else.”

“But what?” John asked, tilting his head.

“I don’t know,” Sherlock replied, and there was a frustrated edge to his voice that John had rarely heard there before. “None of this adds up. It doesn’t match even the acts of a madman. Nothing adds up.”

“Well, if anyone can work it out, it’s you, Sherlock,” John said with a smile. He felt an odd edginess too, but he didn’t want to let it show. “Stop fretting.”

Sherlock gave him a thin grin. “Appealing to my ego to get me to shut up?”

“A little,” John replied with a chuckle. “But it works.”

Sherlock was opening his mouth to reply when a tinny ringtone erupted from a nearby table. It was Sherlock’s, but the man made no move at all. Finally John sighed and stood to get it, handing the phone over to Sherlock to let him answer it.

“Detective Inspector, any news?” Sherlock said into the phone, leaning back in his chair. He was silent for a few moments, then spoke again. “…I see. Of course. We’ll be over shortly. Keep Donovan and Anderson away from it.”

He hung up the phone, sliding it into his pocket. “We’re off, John. Our outlying case, the oldest victim, has been identified - and we have his camera.”

John stood, rushing to get his coat, before following Sherlock down the stairs.

—-

“He was in university,” Lestrade said as the three of them headed down the halls to the evidence room. “A photography student, to be exact. They had some sort of… long-term project, and his was based around Penn Wood. So that explains what he was doing there, at least.”

“The only one with an explanation,” Sherlock murmured. “And we have the camera?”

Lestrade nodded. “His dorm mate found it for us. Said he’d been obsessive about his pictures lately - he used to be a bit of a slacker, but he was going out to Penn Wood daily. Baffles me. The roommate had glanced through the photos, apparently, but not seen anything in particular.”

They stepped into the evidence room then, and Sherlock headed over to the small digital camera immediately, picking it up. “Digital. Rare for a professional.” He looked up at Lestrade. “Did he have another?”

Lestrade nodded. “But we don’t know where the film went.”

“Well, we’ll see what we can find on this.” Sherlock flipped on the camera, starting to look over photos through the preview screen. “Fascinating. A few test shots for projects, a great deal of photos of parties and girls of various sorts - some that I doubt knew about their great contributions to the body of the photographic art - and then just shot after shot of the woods…” He paused then, going still, his already pale skin looking a little paler.

John looked at him, concerned. “Sherlock?” Sherlock rarely, if ever, looked like that.

“I believe we’ve found a photograph of our suspect,” Sherlock said, licking his lips slightly. “He’s… not exactly what I expected.”

John went to Sherlock’s side then, peering in at the camera. At first glance it was just a shot of trees through mist, nothing spectacular - but in the background a figure could be seen, thin and tall. Too tall. John realized with dawning horror that, if perspective hadn’t been played with, the man was only a little shorter than the tree next to him.

And his face was--was--

(his face was terrible beyond comprehension, and beautiful beyond any words, and his face was everything, barely contained by a thin layer of white, and John longed to reach out and pull away that flimsy mask and gaze on the beauty and the horror just beneath the skin and be consumed by it in one perfect moment)

“John?” Sherlock was demanding, somewhere far away. There was a slightly edged, hysterical tone to his voice. “John, what in God’s name are you doing?”

John shook his head, slowly coming back to reality. The moment passed and faded, and he found he could not quite remember just what he had seen. Now there was just the figure on the grainy display, thin and tall and eerie but nothing more than an image in a picture. “I… nothing. Sorry, didn’t sleep well. So… how can someone be that tall?”

Sherlock shook his head. “I don’t know,” he murmured, and then said it again with a certain anger and vehemence to his voice. “I don’t know. None of this makes any sense at all. I have all these pieces, but none of them are fitting…”

Lestrade took the camera from Sherlock, glancing over the image, then shook his head and handed it back. “This is out of my depth,” he said flatly. “I’ll leave the camera to you for now. If we find other photos, you’ll be told.”

Sherlock nodded, looking at that photo one more time before shutting off the camera. “Right, then.” He took a deep breath, straightening. “This will be solved, Detective Inspector. I won’t let some--some man on stilts stop me.”

 _Those weren’t stilts,_ John thought, but he voiced nothing. He was on edge. Sherlock was on edge. He’d let it pass.

(But as they walked out of the building together, John kept thinking about that face, again and again.)

—-

The evening was spent pacing, thinking, going over the photographs and the drawings and working out theories. John threw out a few bits of speculation - a trick of the lens in that photograph, some sort of statue set out to scare the college student, even stilts - but Sherlock shot each of them down. There was nothing consistent. Nothing that fit.

At some point, John got out a notepad and a pencil, planning to document their ideas and take notes for his blog. He watched Sherlock pace and talk to himself, John’s hand dancing over the paper almost with a will of its own.

But when he looked down at the page, there were none of the notes he had thought he had been writing.

Just an X crossing the page, the paper nearly torn by its lines, with a circle wrapped around its arms.

John shuddered and set the notepad aside, face-down. He’d worry about notes later, he decided. He was tired. He’d sleep. He’d rest.

He disappeared off into his room, leaving Sherlock to pace the carpet. John found himself coughing into his sleeve as he started to dress for bed, a violent, wracking cough, but somehow he found himself almost unconcerned.

—-

_He had his orders, and he was a good soldier. Good soldiers obeyed. Good soldiers did as they were told. And if he was very good he would get to feel his master’s embrace break his bones one by one. He craved that in a way that transcended want and became need, a desire that ached beneath his skin (and skin was so thin, so breakable, just a mask hiding what was really beneath the bones and the muscles and the organs and the heart)_

_Knife and rope and tape and there were screams and struggles but he was a good soldier and he had his orders. It was so simple to obey. He just had to obey. It was all so easy. And he smiled and his master smiled without a mouth (but of course he had a smile still it was just hiding) and it was so damn easy._

When John woke up with a start, seeing Sherlock standing by his bed, somehow he already knew what news would come.

“John, the roommate’s vanished.”

**Notes for the Chapter:**

> Thanks again to firegrowshigher @ tumblr for all her help!
> 
> The next chapter will be an intermission of sorts.


	3. Chapter 3

**Summary for the Chapter:**

> An intermission.

_Notes from a government file, deep in a nondescript filing cabinet:_

The entity seems to be attracted, in some way, by knowledge of itself, making it a form of memetic virus. Those who are stalked by the entity speak about it, causing those they tell to be stalked in turn, and so it spreads. The one certain vector leading to inevitable Case 1 or Case 2 scenarios is seeing the entity visually, be it in person or through photography or film. 

Drawings do not have this effect, although prolonged viewing of drawings can draw the entity - any prolonged exposure to knowledge about it risks the danger of drawing the entity's attention. Visual contact is the only certain confirmation, but any knowledge is dangerous. 

The circle-X symbol produced by those infected may be a transfer mechanism - it is unknown if the symbol alone can draw the entity's attention, but it contributes to curiosity and leads to investigation. See Appendix C for notes on the symbol's possible meaning.

In the end, though, the facts are simple. The entity cannot be killed, despite our attempts to do so. We have lost too many good men on our attempts. I myself have lost nearly 40 pounds and seem to be unable to stop coughing - while I seem to have avoided personal attention, the illness brought on by my knowledge may not ever fully heal.

The only solution is to ignore the entity. Any talk of it will only infect others. Even this report is a danger, and I recommend burning it when you are done with it. There is no way to handle this other than to let the knowledge die out. Hopefully the entity will die with it, but I have my doubts. It's survived for centuries, the word spread on through any medium possible, and I don't think we'll be the ones to kill it.

Burn the report. Don't look at the photos. Let it die.

-MH

**Notes for the Chapter:**

> Things like this will be coming between chapters from now on. Hope you enjoy! Working on Chapter 3 proper.


	4. Chapter 4

**Summary for the Chapter:**

> Sherlock and John investigate the latest development, and then go back to the woods to hunt for the culprit. But something else may have found them first.

"So, the roommate just disappeared?" John said, following Sherlock down the steps. He had gotten enough time to dress and grab a slice of bread, but that was all - Sherlock was visibly eager to see the crime scene himself.

"It seems that way," Sherlock replied, pulling his scarf around his neck as he moved. "He didn't go to classes after Lestrade left him yesterday, he didn't attend a party he was meant to go to, he's not answering calls, and one of his friends checked in on his dorm to find it a mess and him gone. Lestrade's there now."

John nodded - then nearly fell as a coughing fit hit him hard. He managed to catch himself against the wall, holding his hand over his mouth. The coughing didn't stop.

"John, is this going to be a problem?" Sherlock said, frowning. "I can investigate the scene without you if you're ill. I'm certain Mrs. Hudson would be willing to make you tea. If you're going to slow down the investigation at all..."

John wanted to head back upstairs and climb into bed - he was seriously ill, he could tell - but something told him not to. He wanted to see the scene. And besides, he was sure he could manage a few hours on his feet, if only to show Sherlock that he wasn't an inconvenience.

"It's just a cough, that's all. Probably dust in the air." John managed a thin smile. "I'll be fine, Sherlock. C'mon, let's go find a cab."

Sherlock hesitated a moment more, then nodded and headed out the door.

John followed after, pausing once to glance at the hand he had coughed into.

There were a few small flecks of red on it.

He wiped it clean on his trousers and climbed into the car next to Sherlock, resolving to worry about it later.

\---

When they arrived on the scene, the caution tape was already up, the room scoured over. Lestrade and one other officer were the only ones there, looking over the evidence together.

The dorm was a wreck, but it wasn't traditional college clutter. Most of it was paper waste; there were papers scattered everywhere on the floor. Some held drawings of trees, or too-familiar blank faces. Some still were covered in scribbled, illegible writings. John picked one up to study it, shaking his head as he looked over the script.

_he sees me HE SEES ME_

It was then that John noticed the red stains on the edge of the page and shuddered, dropping it. It was obvious that this wasn't just an average student playing hooky.

He looked up then and saw the symbol - an X in a circle, carved into the plaster of the wall with something sharp, the lines dug in deeply. He shivered, looking at it, but he was somehow entranced too. He found himself running one hand along one of the lines of the X, feeling the shape under his fingers.

"Was the roommate acting oddly when you saw him before?" Sherlock was asking Lestrade, somewhere behind him. John managed to get himself to turn and look.

"A little," Lestrade admitted. "He seemed a bit pale, and there were papers around that we didn't look at too much. We took it for just normal pre-exam stress, coupled with finding out his roommate was dead."

"And of course you never thought to tell me, to let me talk to him," Sherlock muttered, annoyed. "Lovely. A potential lead gone before I knew it existed." He glanced at the symbol. "At the least, we have something like a motive now."

"Do we?" Lestrade asked, tilting his head.

"Our killer is somehow finding the people who know about him and killing them. The children are probably his only personal targets - some sexual thing, probably, it usually is - but anyone who notices him has to die too. It's a remarkably stupid decision, though. The roommate barely knew anything, he had just seen one blurry photo at most. And the fact he hounds them first, gets them all psychologically worked up... it's more attention." Sherlock frowned a little more.

"Maybe he wants people to know about him," John said, and the words seemed not quite his own on his lips and tongue. "To find out who he is. Maybe he wants more prey to hunt, more people to bring with him. More people to have their eyes opened, so they can see, see his face, see what's behind that mask..."

Sherlock stared at John, and he looked a little paler than usual. "Are you feeling alright, John?" he said, and there was a doubt in his voice that John had never heard before.

John shook his head, clearing it. "I'm... I'm fine. I'm sorry. Just didn't sleep well last night, and now that I have a cold..."

Sherlock nodded firmly. "Well, we're done with this, I think. No signs of the perpetrator - he took the roommate from somewhere else. And I have one firm idea." He turned to Lestrade. "We're going to the woods, Inspector. You should head back to Scotland Yard, but be cautious." He grinned, mirthlessly. "After all, we're all targets."

\---

Penn Wood was as John remembered it from the last trip - cold and soggy. He assumed it probably looked better in seasons other than winter, but at the moment it was a bit of a wreck. The trees were tall and skeletal, reaching bare branches to the sky, and he felt a brief tremble of fear at the sight of them.

Sherlock seemed utterly unbothered by the damp leaf cover and the narrow, barely-there trails they had to follow, but John found himself scratched up by branches and with soaked-through shoes within minutes. He wasn't even really surprised. Sherlock had no time for things like dampness.

Finally they made it to the clearing where the bags had been hanging a few days ago. The caution tape had been stripped down, leaving just a few tattered shreds - John noticed that before he entered the clearing proper.

When he did step into the clearing, though, he nearly vomited.

There was a man stretched out on the leaf litter, eyes open, staring blankly at the branches overhead. His torso had been cut open, and in the brief glance John managed before he had to look away he saw that the torso was hollow, the ribs snapped away and the organs beneath removed. His blood stained the clearing. John could handle death, but this was something else.

"He's changed his methods," Sherlock was saying, and John could hear a hint of tremble in his voice too. "Changed the game. Not much, but enough to be noticeable. But why? What does this mean, John?"

"I... I, oh God, I don't know." John tried to clear his head, to look at Sherlock again. "I don't know..."

And then his lungs seized up and he began to cough again, harder than ever before, hard enough to send him crashing to the ground. He spat blood onto the leaves, pain aching through his body with every wrenching cough.

Sherlock moved to kneel by him, wearing an expression John didn't recognize. "John, what--"

But then whatever he was saying was cut off as a shadow fell over them both. Sherlock looked up, his face going pale, his eyes wide, his body trembling.

It took a few moments, but John forced himself to look up as well. When he finally caught sight of the figure the pain disappeared from his lungs in a moment.

 _he was tall almost as tall as the trees but he did not have to bend they bent aside for him he was one of them and he was black and white and colors that could not be seen by human eyes and he had so many arms arms like branches reaching high and his face was blank and white and empty of meaning but nonetheless when he reached out a writhing, twisting arm for John he_ smiled--

John awoke with a gasp, sitting up, shaking. The sky through the trees was utterly dark except for the thin sliver of the moon, and he was freezing cold. It was night, he could tell that much, and a glance around him told him that they were at the edge of the woods instead of in the clearing they had been in before.

There was something sticky beneath him, pulling at him when he went to sit up. He lifted one hand to his face, managing to get his hand close enough so that he could make out the colors in the dim moonlight.

Red-brown, thick and shiny. Blood. He was laying in a puddle of blood.

"Sherlock?!" he screamed, afraid in a way he had never felt before. "Sherlock, where are you?!"

"Here, John," came Sherlock's voice, and it was raspy and choked.

Sherlock was hunched up under one of the trees, his position nearly fetal. John could make out the smears across his skin, dark in the moonlight but shining just a little here and there. More blood. 

In moments John crawled to Sherlock's side, hesitantly wrapping an arm around the man's shoulders. Sherlock leaned against him, and they stayed that way in silence for a few minutes, both of them trembling.

"What was that?" John said at last, not wanting to ask but having to hope that maybe, maybe, Sherlock had worked it all out, solved the problem.

"I don't know," Sherlock replied, and his voice was almost pleading. "I don't _know_."

They sat that way in the dark for a long, long time.

**Notes for the Chapter:**

> Thanks to my lovely girlfriend/beta/ideas girl, firegrowshigher. Kisses! <3

**Author's Note:**

> Thanks to firegrowshigher @ tumblr for being my brainstorming partner - she has a bunch of great ideas, and I couldn't do this without her. <3
> 
> Chapters will come somewhat erratically.


End file.
